Computer-pointing devices are often used in connection with computers to facilitate entry of user input and to enhance the functionality of the computers. One common type of computer-pointing device is the cord-based mouse. This type of mouse is connected to the computer by a cord and is moved over a pad to effect movement of the cursor displayed on the monitor of the computer. When the cursor is positioned at the desired location, actions can be invoked by clicking on one of the mouse buttons. Using the mouse in this manner allows a computer user to navigate through graphical user interfaces displayed on the computer monitor quickly and easily thereby facilitating user access to various files and programs.
Although this type of mouse is satisfactory for the most part, problems do exist. Since the mouse is physically connected to the computer by the cord, the cord restricts the movement capabilities of the mouse. If the cord is taut, the user is required to lift the mouse off the pad to provide slack in the cord before placing the mouse back down on the pad. Also, the user is required to navigate the mouse in close proximity to the computer.
More recently, developments in the field of mouse technology have led to cordless mice. As will be appreciated, the cordless mouse overcomes the problems associated with cord-based mice discussed above. However, the cordless mouse suffers from its own disadvantage. Since the cordless mouse is not physically connected to the computer, the mouse is not able to draw power from the computer power supply. Therefore, the cordless mouse requires batteries to provide the power necessary to operate the mouse. Batteries of course require replacing when they run low and replacing batteries is inconvenient. Also, batteries can drain at unexpected and inappropriate times creating user annoyance especially if the batteries drain while the user is in the middle of an important project.
To deal with this power supply problem, a number of self-powered auxiliary input devices have been considered. For example, U.S. Pat. No. 5,838,138 to Henty, entitled “Electronic Device Which is Powered by Actuation of Manual Inputs”, discloses a system having a mechanical power convertor to convert mechanical energy applied to the keys of a keyboard into electrical energy that is used to charge a rechargeable battery. The power convertor includes a thin high strength magnet that is fixed to the central portion of each key. A coil surrounds each magnet. Each coil is mounted on a mandrel that is attached to the keyboard. Current is induced in the coil when the key is actuated.
U.K. Patent Application No. 2,314,470 to Tien, entitled “Battery Charging Arrangement with Inductively Coupled Charging Device and Rechargeable Device”, discloses a mouse accommodating a rechargeable battery that is re-charged by a magnetic field generated by primary and secondary induction coils of a charging device. The rechargeable battery is connected to the secondary induction coil that is displaced from the primary induction coil. The battery is charged when the induction coils are located adjacent one another such that a current in the primary induction coil induces a current in the secondary induction coil.
Japanese Patent Application No. 10283079 issued to Sony Corporation, discloses a mouse with a detection roller that moves in two axial directions corresponding to the rotation of a roller ball. A roller rotation detector senses the amount of movement of the detection roller in the two axial directions. A transmission circuit communicates with the roller rotation detector and converts the sensed movement of the detection roller into electromagnetic signals. Electric power is produced by a generator in response to the electromagnetic signals. The produced electric power is stored by a secondary battery and supplied to the transmission circuit. Although this reference discloses a mouse including a mechanism to generate power, problems exist in that since the detection roller moves in two axial directions, the mouse is subject to mechanical failure.
As will be appreciated, improvements to cordless computer-pointing devices are desired. It is therefore an object of the present invention to provide a novel self-powered computer-pointing device.